Fuse cut-out



A. RAMSEY FUSE GUT-OUT Aug. 31, 1937.

Original Filed Aug. 28, 1931 6 Sheets-Sheet l Aug. 31, 1937.

A. RAMSEY FUSE CUT-OUT Original Filed Aug. 28, 1931 6 Sheets-Sheet 2 JZZZanWsgy (Q; Wm mm A. RAMSEY FUSE CUT-OUT Aug. 31, 1937.

Original Filed Aug. 28, 1931 6 Sheets-Sheet I5 A. RAMSEY FUSE CUT-OUT Aug. 31, 1937.

6 Sheets-Sheet 4 Original Filed Aug. 28, 1931 A. RAMSEY Aug. 31, 1937.

FUSE CUT-OUT Original Filed Aug. 28, 1931 6 Sheets-Sheet 5 A. RAMSEY FUSE CUT-OUT Aug. 31, 1937.

Original Filed Aug. 28, 1931 6 Sheets-Sheet 6 Patented Aug. 31, 1937 I'U SE CUT-OUT Allan Ramsey,

Evanston,

11]., assignor to Schweitzer a Conrad, Inc., Chicago. Ill., a corporation of Delaware Application August 28, 1931, Serial No. 559,848

Renewed March 22, 1837 714 Claims.

the particular use or specific details herein illustrated and described.

Devices of this sort commonly have a box provided with a front opening andcommonly have a cover hinged to the box for closing the front opening and swingable away from the front of the box to open said opening. These devices also have been provided with contacts mounted within the box and the fuse has been mounted upon the cover and provided with contacts adapted for engagement with the contacts in the box when the cover is closed.

Heretofore in the art the spring contact clips usually have been mounted in the box and the sides of the metal ferrules mounted on the insulating casing usually have been splayed for contact with the spring arms of the clips. The spacing of the hinge for the cover from the lower or adjacent contact mounted on the fuse for engagement with the spring contact clip mounted in the box must be sumcient to secure the desired movement of the fuse contact with respect to the contact in the box, and particularly the desired separating movement. of the fuse contact from the box contact in opening the cover. With the arrangements previously provided, as above pointed out, this has required projection of the hinge from the box, and particularly a greater over-all length of the device than would be otherwise required. The prior art devices have also been of greater width than the fuse element structure; and other improvements which will hereinafter appear.

According to the present invention, I mount the spring contact clip on the fuse and arrange this clip for movement, upon closing and opening the cover, into and out of engagement with the contact member mounted within the box. The spring contact clip preferably extends laterally from the insulating casing of the fuse, or where the fuse casing is provided with a ferrule, as above pointed out, the spring contact clip may extend laterally from the ferrule and may, in that case, be mounted upon the ferrule. This mounting of the spring clip upon the fuse and its lateral extension therefrom disposes the contact portion thereof for engagement with the contact mounted within the box in position offset laterally with respect to the fuse, and particularly in position offset laterally from the fuse in the direction of swinging movement of the cover. This enables providing a shorter box and bringing the hinge member for the cover nearer to the stationary contact within the box, and the distance between the mounted end of the stationary contact member and the fuse is utilized in attaining the desired spacing of the hinge from the position of contact between the spring contact member on the fuse and the stationary contact within the box.

The improvements above referred to, and other improvements to which I have not heretofore specifically called attention, will be apparent from the following detailed description and the claims.

Now in order to acquaint those skilled in the art with the manner of constructing and operating a device embodying my present invention, I shall describe, in connection with the accompanying drawings, a specific embodiment of the invention.

In the drawings:

Figure l is a vertical longitudinal section through the fuse box of a device embodying my invention, showing the cover in closed position and the fuse and contact parts in elevation;

Figure 2 is a similar view showing the cover in open position;

Figure 3 is a front elevational view showing the cover in open position with fuse tube removed;

Figure 4 is a transverse section taken on the line 4-4 of Figure 1;

Figure 5 is a transverse section taken on the line 5! of Figure 1;

Figure 6 illustrates in front elevation the fuse casing with the ferrules and spring contact clips mounted thereon;

Figure '7 is a side elevational view of the same;

Figure 8 is a top plan view of the upper contact ferrule;

Figure 9 is a bottom plan view ofthe lower contact ferrule;

Figure 10 is a side elevational view of the lower contact ferrule with spring contact mem- 10 bers omitted;

Figure 11 is a side elevational view of the upper contact ferrule with spring contact members omitted;

Figure 12 is a longitudinal section through the fuse device shown in Figures 1 and 2;

Figure 13 is a side elevation of one-form of fuse element as it appears before being placed in fuse casing; I

Figure 14 is a detail transverse section taken A on the line I8H of Figure 13;

Figure 15 is a detail transverse section taken on the line i5-l5 of Figure 13;

Figure 16 is a view similar to Figure 13, showing another form" of fuse element as it appears before being placed in fuse casing;

Figure 1'7 is a view of the fuse element shown in Figure 16 and taken substantially at right angles to Figure 16;

Figure 18 is a fragmentary view of the lower end of the insulating'casing of the fuse, showing a contact ferrule mounted thereon and adapted for use with the fuse element of Figures '16 to 17, inclusive;

Figure 19 is a bottom plan view of the contact ferrule shown in Figure 18;

Figure 20 is a side elevational view of a terminal member adapted for attachment to the lower end of the fuse spring and for use with the fuse element shown in Figures 16 to 17, inclusive; and I Figure 21 is a lower end view of the terminal member shown in Figure 20.

The fuse box 5, which is adapted to be exposed to the weather and houses the high voltage fuse, comprises a unitary body member consisting of a back wall member 6, from which extends forwardly an integral rim 1 defining substantially parallel side walls 8, 8 and a top wall 9 and leaving the front open at it and the bottom open at H. The back member 6 and rim 1 preferably are formed as a unitary piece of dense wet process porcelain. The entire box 5 preferably is glazed and the glaze may be colored to provide the desired color and finish.

The back 6 preferably has an inwardly thickened portion 12 between its upper and lower ends, and the inward intermediate extension formed by this thickened portion preferably extends between the side walls 8 and preferably is integral at its oppositeends'therewlth, thereby providing lateral reenforcement between the side walls along the back and between their upper and lower ends. The side walls 8, 8 may be provided with integral ribs i 3, as shown in Figures 4 and 5. A pair of pockets or depressions i4 ened back wall portion I2 and the other below that portion. The stationary contact members l6 and I! are mounted within these pockets and upon the back wall member 6. The top wall 9 and side walls 8, 8 have a continuous projecting rim l8 which embraces the periphery of the cover member when said member is closed and thereby acts as a water shed to prevent the entrance of moisture into the fuse box.

and iii are thereby formed, one above the thick- The cover 20 is in the form of an integral unit of suitable molded insulation, such as a phenolic condensation product or the like, its inner surface being depressed centrally at 2| (Figure l), and its outer side being provided with an eye 22 formed integral with the cover and having a central perforation 23. This eye 22 is adapted to receive the end of a hook stick whereby the cover may be manipulated to closed or open positions. The cover 20 has an arm or integral extension 24 provided with an integral boss 25 which, with the adjacent end of the arm, fits between the side walls 8, 8 at the lower end of the device. The end of the arm 24 with the connecting boss 25 has coaxial openings 26 for receiving the reduced inner ends of pivot pins 21, the enlarged threaded outer ends of which have threaded engagement in metal inserts 28 molded ri idly in the side walls 8, 8. These pivot pins 2'! are screwed into place from the outer sides ofthe walls 8 by screw-driver kerfs, and the cover 20 is hinged in place by inserting the arm 24 with the connecting boss 25 between the lower ends of the walls 8, registering the openings 26 with the threaded openings in the inserts 28 and threading the pins 27 inwardly to engage their inner reduced ends in the openings 26.

The upper stationary contact member i6 comprises a plate portion 38 having on its rear side' I integral studs 3i cemented at 32 in cementing recesses 33 in the back wall member 6. The inner surfaces of the recesses 33 may be corrugated or roughened as showmand the studs 3i preferably are tapered with their larger ends disposed toward the bottoms of the recesses for the purpose of secure anchorage therein. Projecting from the front ofthe plate portion 30 is an integral contact lug 3d centrally disposed between the opposite side walls 8 and having its forward end tapered or beveled as shown for entry between the sides of the cooperating spring contact clip 35. Also formed integral with the front side of the plate portion 30, of the stationary contact i6, is a transverse lug 36 having a transverse openings? extending entirely therethrough for the purpose of receiving the bared end of the line wire from either side of the terminal. Screws 38 are provided for binding the inserted end of the wire firmly in place.

The lower stationary contact H has a plate portion All provided on its inner side with integral studs ll similar to the studs 31 of the upper contact and cemented at 32 in cementing recesses 43 in the back wall member 6 similar to the cementing of the studs 3! in the recesses 33. On its forward face the plate portion 40 of the contact member I! has an integral contact tongue 44 disposed centrally between the side walls 8. Also formed integral with the contact i! is a transverse lug 45 having a transverse opening 46 extending entirely therethrough for receiving the bared end of the line wire from either side of the terminal, and screws 41 are provided for binding the inserted end of the wire in the opening 46.

A pair of metal inserts 50 molded in the back wall member 6 are provided for the purpose of mounting the box uponv a suitable support (not shown). These inserts 50 have threaded sockets 5| for receiving screws for attaching a bracket or'other support to the back wall member of the box. When mounted in place upon its support the top of the box'5 preferably is tilted forwardly slightly, as shown, for the purpose of further assuring against the entry of water into the box,

but, of course, it is to be understood that this may vary within the scope of the present invention.

As shown in Figure 3, a pair of perforations 52 are formed in one of the side walls 8 to permit extending the respective conductors into the fuse box to the respective stationary contact members 15 and 11. Similar perforations 53 are provided in the opposite side wall 8. The purpose of perforations in both side walls is to permit the extension of the conductors into the fuse box from either side. perforations 52 and 59 preferably are inclined upwardly through the side walls, as shown, for the purpose of preventing moisture from entering the box through these openings. The outer ends of the openings 52 and 53 may be provided with surrounding water sheds'54 formed integral with the side walls 8.

The fuse comprises a casing 58 in the form of a cylindrical tube. This tube is preferably formed of a hard insulating fiber known as Conite which does not carbonize under heat but it is to be understood that any other suitable or preferred insulating material may be employed. A ferrule 59 of cast hard bronze or other suitable or preferred material fits over the upper end of the tube 58 and is rigidly secured thereto by means of a. pair of screws 58 and GI (Figure 7). These screws are threaded through diametrically opposite sides of the ferrule and into the wall of the tube, the upper end of which may be reduced to seat the lower end of the ferrule at 52. The upper end of the ferrule 59 has a pair of laterally extending arms 53 formed integral with the ferrule and spaced below the arms 83 is a second pair of generally parallel arms 64 also formed integral with the ferrule. Extending diametrically oppositely from the arms 83 and 54 and integral with the ferrule 59 is a book 65 provided for the purpose of attachment of the upper end of the fuse to the cover 28. At generally right angles to the arms 53 and at the opposite side of the ferrule 59 and integral therewith are a pair of diametrically opposite lugs 55.

The upper spring contact clip comprises a plurulity of laterally extending and generally parallel contact wires preferably of copper and preferably with inherent springiness, that is, under initial tension, although this may vary. These contact wires are indicated at 68, there being in the illustrated embodiment four of these wires in superposed relation on each side and between each arm 83 and the underlying arm 54. The ferrule ends of the contact wires 58 fit snugly and are firmly and rigidly secured in openings 59 in the lugs 58, being adapted to be secured therein by prick punches 18 in the lugs 55 between the anchored ends of the contact wires as shown. The outer ends of the wires 58 are looped at 1| to form substantially toroidal contacting portions that provide substantially point contact or engagement of very small area in cooperating with flat or convex contact surfaces and pins 12 formed of brass rod or othersuitable material extend through these looped ends 1| and are anchored at their opposite ends in the arms 63 and 54. The looped ends 1! are the contact ends and the pins 12 hold these ends in place and against undue displacement, but at the same time fit suiliciently loosely in the looped ends 1i to permit freedom of separation and closing of these ends upon the contact lug 34 by their own inherent resiliency. It will be observed that the T a inner ends of the looped ends 1| of the wires 58 bear against the outer surface of the pins 12-12. The wires 58 are initially formed so that without the restraining effect of the pins 12 they will approach each other much more closely than shown in Figure 8. The pins 12, however, hold these wires back in a predetermined position, thereby producing a condition of initial tension or inherent resiliency, as explained in my copending application, Serial No. 445,548, filed April 19, 1930. This prestressing or inherent resiliency provides a high spring pressure with minimum displacement when the cooperating contact 34 enters between the jaws. Washers 13 (Figure 7) on the pins 12 and between the respective looped ends of the contact wires 88 and between the arms 53 and 84 and the uppermost and lowermost contact wires provide spacers for spacing and maintaining the desired relative positioning of the looped ends of the contact wires.

The lower ferrule 18 of cast hard bronze or other suitable material is split at 19 and clamped by screws upon the tubular casing 58. This ferrule 18 has the upper laterally extending arms 8| corresponding with the arms 53 of the upper ferrule and the lower laterally extending arms 82 corresponding with the lower laterally extending arms 54 of the upper ferrule. The contact wires 83 are similar to the contact wires 58 of the upper ferrule and their ferrule ends are anchored in openings in lugs 84 similar to the anchoring of the ferrule ends of the upper contact wires, prick punches 85 being provided in the lugs 84 between the anchored ends of the wires 83 as in the upper ferrule. The outer looped ends 85 are similar to the outer looped ends 1 I, and the pins 81 passing through these looped ends 85 and anchored in the arms 8i and 82 correspond with the pins 12. The wires 83-83 bear against the pins 81 and are held by these pins from approaching each other more closely, which they would do if the pins 81 were withdrawn. The wires 8383 are, like the similar wires 58-68, prestressed and held against displacement towards each other by the pins 81-81, so that upon the entry of the lower contact member 44 between them a high degree of pressure is attained, with a minimum displacement of the curved ends 85--85. The washers 88 space the looped ends of the contact wires 83 and correspond with the washers 13 of the upper ferrule. Integral with the lower ferrule 18 is a skirt portion 89 partially embracing the casing 58, and a latch lug 98 also is formed integral with the ferrule 18 for a purpose which hereinafter will appear.

The upper end of the ferrule 59 is threaded internally,asindicated at 92 (Figure 12) to receive a cap nut 93. This cap nut 93 has a hexagonal head 94 to facilitate turning the same into and out of the upper end of the ferrule 59. The cap nut 93 closes the top of the tube 58. This cap nut 93 has an integral axial boss 95 extending into the tube. The boss 95 has a helical groove 95 for receiving the upper end of the spring 91 by threaded engagement therewith.

The boss 95 is reduced at its lower end and has a socket 99 in which one end of a flexible braided conductor I00 is rigidly secured. This braided conductor I00 is made of copper or the like and its opposite end is connected with the lower terminal member 102 by rigidly securing it in the socket I03. The lower terminal has a helical groove formed therein for threaded engagement with the lower end of the spring 91, and the lower terminal is thus suspended by the spring. This lower ter- 75 minal I02 has a flattened portion I05 to receive a stud I05 which may be then lodged in place by means of a pin I07. The fuse link I08 extends around the stud I05 and is bolted to the terminal 5 I02 by means of a nut I09 threaded upon the stud The stud M6 is threaded throughout its length and is undercut at approximamly its center, as indicated at I I I. One end of the fuse link I05 10 is secured to the terminal I02 within the fuse casing 58 by means of the stud Ida and nut I09 as previously pointed out, and the terminal Id? is then drawn downwardly as by means of the fuse link I08 thereby placing the spring dl under tension. The opposite end of the link I08 is then secured to the stud M0 by means of a nut H2 threaded upon the extending end of the stud M0. A circuit is thus established from the fuse to the lower ferrule I8.

The fuse link is made of suitable fusible material as, for example, pure silver wire and it has a portion II5 of reduced cross-sectional area at a point along its length within the tube 56, said reduced portion H5 being surrounded by a cork I I6 disposed within the lower end of the tube 50. When the fuse link blows it blows at the reduced portion I I5 and the tension of the spring 01 being thereby released, this spring will quickly snap the terminal I02 upwardly and away from the point of blowing of the fuse to draw out quickly and extinguish any arc that may form.

Mounted upon the cover 20 in proximity to the lower terminal of the fuse is a fuse tube holder I20. This holder I20 comprises an angular bracket having a relatively long leg secured to the cover 20, and another leg extending at subi stantially right angles thereto and terminating in an upturned end I 2i adapted to engage the lug 90 on the lower ferrule I8 to support the fuse 40 upon the cover and hold the same thereto. v Also mounted upon the cover 20 is a catch I24 for the upper contact clip. This catch has a lug I25 at its lower end and spaced upwardly from the lug I25 is an integral hook portion I 25 adapted for hooking engagement with the hook 65 on the upper contact clip for the purpose of holding the upper end of the fuse in place upon the cover. The fuse is applied to the cover by placing the lower end of the fuse tube between the upturned legs of the bracket I20, the upper end being in position far enough to the right or left of the center of the cover to enable the hook 65 to be moved sideways into engagement with the catch I24. The point of the flat spring 300 attached at 30I to catch I24 engages the rounded notch 302 in hook 65 to hold the fuse tube in position at the center of the cover. The fuse tube is removed from the cover by moving the upper end of the tube sideways until the hook 65 is released from the catch I24 and then moving the lower end of the tube out of engagement with the bracket I 20.

For the purpose of latching the upper end of the cover 20 in closed position, a pair of spring tempered metal latch arms I30 are provided. These latch arms I30 (Figure 5) are secured by screws I32 to the opposite side of the lug 31 of the upper stationary contact I6, and their free ends are looped at I34 for engagement with shoulders I35 on the upper ferrule or contact clip 59. The screws for fastening the upper catch I24 to the cover 20 are indicated at I38 in Figure 5, and the screws for fastening the lower tube holder I20 to the cover 20 are indicated at 7 I30 in Figure 4.

accuses From the foregoing it will now be apparent that, assuming the cover 20 isin open position, as shown in Figure 2, upon swinging same to closed position the springcontact clips are moved into contact with the stationary contacts It and Ill and the shoulders I30 are'sprung into engage= ment with the looped ends lid of the latch am 686, which by their inherent resiliency or apringi ness spread to permit movement of the upper contact clip therebetween and then spring in behind the shoulders I35 and latch the cover in closed position. The cover is opened and the circuit through the device broken thereby by engaging the eye 22 and drawing the cover out-= wardly in a clockwise direction away from the open front of the box. This releases the upper contact clip from the latch arms I35 and the opening movement of the cover withdraws the spring contact clips on the fuse casing out of engagement with the stationary contacts It and It will be noted that when the cover is closed with the circuit through the fuse closed thereby, the spring contact clips on the fuse engage the stationary contacts mounted within the box in position ofifset laterally with respect to the fuse device, and particularly in the direction of swinging movement of the cover. This enables bringing the hinge 20 up within the lower end of the box and without extending the same outwardly beyond the open front of the box. The over-all dimension of the device longitudinally is thereby reduced and at the same time this, with the character of the stationary and spring contact clip arrangement, enables reduction of the width of the device. The space between the stationary contacts and the fuse casing is utilized to obtain the desired positioning of the hinge 26 and the result is a device which is compact and without undesirable projecting brackets and the like.

The lower end of the fuse is positioned and operable through the bottom opening II and the lower edge of the back wall 6 adjacent this opening may be inclined as shown at I50.

In the embodiment of Figures 18 and 19, the lower contact clip or ferrule 200 is provided with a button 20I instead of the pin IIO and nut II2 of the previous embodiment. This button 20! may be formed integral with the clip or riveted or otherwise rigidly secured thereto. The lower fuse terminal for use with this device in place of the terminal I02 of the previous embodiment is shown at 202 in Figures 20 and 21. This termi nal 202 has a button 203 riveted thereto at 204.

The fuse element shown in Figure 13 comprises a short length of copper tubing 205 and a somewhat longer length of copper tubing 206 flattened and thereby secured upon the opposite ends of the closed loop strain element 201 and upon the opposite ends of the crimped fuse wire 200. The fuse wire 208 preferably is of pure silver, and the strain element 201 preferably is made of a nickel chromium alloy known on the barket as Chromel A wire. The cork inclosure 209 surrounds the fuse element and strain wire assembly as shown, and this cork member 209 is made up of two half round corks having complementary depressions 2I0 and surrounded and held together by a water-proofed paper tube 2. The silver fuse element 200 is enclosed in thin sheet mica at 2l2 to prevent contact with the strain wires 201 and to keep heat from the fuse element from charring the cork. The flattened section of copper tubing 206 has an eye 2I4 which may be secured to the lower inside and movable terminal as described H6 is so that it maybe grasped conveniently for the purpose of setting the fuse.

The fuse element illustrated in Figures 16 and 17 is similar to that shown in Figures 13 and 14,

15 and like or similar parts are indicated by primed reference characters similar to those employed in connection with Figures 13 and 14. This element, however, has looped terminals 250 and 25l made from stranded conducting cable. The loop 20 250 is adapted to hook over the button 200 of the terminal shown in Figures 20 and 21, whereas after setting the device and extending the element down around the lower end of the casing,

the loop 252 in the other terminal 25l is adapted 25 to hook over the button 20l on the lower contact clip or ferrule 200 of the fuse and externally of the fuse casing. The looped extension 250 is of soft copper wire or other suitable material and isadapted to be conveniently grasped for the pur- 30 pose of setting the device.

The inner surface of the button MI is inclined or tapered at 005 and the inner surface of the button 208 is inclined or tapered at 306. These inclined surfaces give the spaces 30! and"! for the cable loops 252, 250 wedge-like formations so that proper contact of the cable loop 250 with the button 203 and proper contact of the cable loop 252 with the button 201 is obtained by virtue of the wedging action of the cable loops 250 and 252, 49 shown in Figures 16 and 17, in the spaces 308, 301 and with the wedging or inclined surfaces 306 and 505 of the respective buttons. The spring tension on the element, Figure 16, by the spring corresponding with the spring 91, Figure 12,

. causes the cable loops to wedge under the butj tons. This is an important aspect of the present invention.

I do not intend to be limited to the details shown or described, as they may be varied within 50 the skill of those practiced in the art, without departing from my invention.

I claim: 1. In combination, a box, a cover for said box hinged thereto to swing vertically, contacts in -said box, an electrical connecting device carried by said cover and adapted for connecting said contacts, and spring stressed contact jaws mounted on andsupported by said deviceindependently of said cover and movable into and out Go of gripping engagement with the contacts in the box.

2. In combination, a box, a cover hinged to the box to swing vertically to open and closed positions with respect to said box, vertically aligned contacts in said box, an electrical connecting device carried by said cover and adapted for connecting said box contacts when the cover is closed, and vertically aligned contacts mounted 75 opening movement of the cover, said box contacts being disposed entirely ahead of the device in the direction of closing movement of the cover when the cover is closed whereby to increase the radius of coaction of the contacts on the device with the contacts in the box, said box having an opening in the bottom through which the lower end of the tube projects when the cover is closed.

.3. In combination, a box, a cover for said box hinged thereto to swing vertically, contacts in said box, an electrical connecting device carried by said cover and adapted for connecting said contacts, and Jaw-like contact means mounted on and supp rted by said device independently of said cover and having engagement with opposite sides of said first contacts.

4. In combination, abox, a cover for said box hinged thereto to swing vertically, a contact in the box, an electrical connecting device carried by said cover, and a multiple spring jaw contact mounted on and supported by said device independently of said cover and projecting laterally from said device for gripping engagement with said first contact.

5. In combination, a box, a cover hinged to the box to swing vertically into open and closed positions with respect thereto, a pair of stationary contacts in the box, an electrical connecting device mounted on said cover and adapted for connecting said contacts and for disconnecting said contacts to interrupt a flow of current, and a pair of spring stressed contacts mounted on said device and when said cover is closed engaging said first contacts solely in position offset laterally with respect to the device in the direction of swinging movement of said cover.

6. A device of the class described comprising a fuse box having a front opening, a cover for i the front opening and hinged on a horizontal axis at the bottom of the box, a pair of contacts mounted inside the box, a fuse mounted on said cover, and a pair of spring stressed contacts mounted on said fuse and engageable with and supported solely by said first contacts.

7. A device of the class described comprising a fuse box having a front opening, a cover for the front opening and hinged on a horizontal axis at the bottom of the box, a pair of contacts mounted inside the box, a fuse device mounted on said cover, and a pair of spring contacts mounted on said fuse device and engageable with vertically extending surfaces on said first contacts, said box contacts being disposed entirely ahead of the fuse device on the cover in the direction of closing movement of the cover when the cover is closed whereby to increase the radius of coaction of the contacts on the fuse device with the contacts in the box.

8. A device of the class described comprising a fuse box having a front opening, a cover for the front opening and hinged on a horizontal axis at the bottom of the box, a pair of contacts mounted inside the box, a fuse mounted on said cover, ferrules mounted on said fuse, and multiple finger contacts mounted on said ferrules for engagement with said box contacts when the cover is closed. I

9. A fuse device of the class described comprising a tubular casing of insulation closed at one end and open at the other, means within said casing for interrupting current flow, multiple spring stressed contact means mounted upon the outside of said tubular casing and extending laterally with respect thereto, said contact means being supported by said casing and having connection with said current flow interrupting means, and means for holding said tubular casing against endwise movement independently of the springcontact means.

10. A device of the class described comprising a tubular casing of insulation, means within the casing for interrupting current fiow, a ferrule member having a split portion embracing the casing and clamped thereon, and spring finger contact means carried by said ferrule, said con- 10 tact means being supported solely by said ferrule and projecting laterally therefrom on each side of the split portion. I

11. In combination, a fuse box, a cover for said box, an angular fusetube holder mounted on said cover and having an upturned lug, a catch mounted on said cover, and a fuse device having a projecting hook engageable with said catchand a lug engageable with the upturned end of the fuse support for attachment of said device to the.

cover.

12. A contact jaw comprising a jaw support having a plurality of rows of apertures, a pinrality of contact wires having ends in proximity to said support and secured in said apertures,

said contact wires lying in spaced rows and hav ing loops at their opposite ends and means passing through said looped ends and secured to said support for positioning the looped ends of said wires in spaced apart relation to provide room between them for the entry of a cooperating contact.

13. In combination, a fuse box, a cover for said box, a fuse mounted on said cover. a'fuse clip mounted on said fuse and having a clip support,

said clip support having a plurality of apertures,

a plurality of contact wires having ends in proximity to said clip support and secured in said apertures, the opposite ends of said cohtact wires having loops thereon, means on said clip support and passing through the looped ends of said wires for positioning the same, and a stationary contact member mounted within the fuse box and engageable between the looped ends of said contact wires.

5 14. In-combination, a fuse box, a cover for said box having hinged connection relative to the box to permit it to swing in a vertical plane, a pair of stationary rigid contact members mounted within the boxin vertical alignment, and a fuse mounted on said cover, said .fuse having a pair of spring stressed contacts for engagement with said stationary rigid contacts.

15. In combination, a terminal member having surfaces, one inclined with respect to the other to form a wedge-shaped space, a fusible element having a looped terminal placed over said first terminal member and in said wedge-shaped space, and means for wedging the looped terminal of said fusible element in the wedge-shaped space of said first terminal member.

16. In combination, a pair of terminal members, at least one of which has surfaces, one inclined with respect to the other to form a wedgeshaped space, a fusible element having at one end a terminal secured to one of said first terminal members and at its opposite end a looped terminal adapted to be placed over the other of said first terminal members and engaged in the wedgeshaped space thereof, and means for placing a spring tension on said fusible element, said spring tension wedging the looped terminal of said fusible element into the wedge-shaped space of said first terminal member.

,- 17. In combination, a movable terminal member having a button provided with an inclined slu'face under its head, a second terminal member also having a button provided with an inclined surface under its head, a fusible connecting element having looped terminals placed over said buttons and under the heads thereof, and means for wedging 5 the looped terminals of said fusible connecting element under the heads of said buttons.

18. In combination, a movable terminal memher having a button provided with an inclined surface under its head, a second terminal member 10 riso having a button provided with an inclined surface under its head, a fusible connecting element having looped terminals wedged under the heads of said buttons, said fusible connecting element comprising a fuse element, and a spring it connected to the movable terminal memberand normally restrained by said fuse element whereby the terminals of said element are held wedged under the heads of said buttons and in wedging contact therewith. 20

19. A device of the class described comprising a fuse box adapted to be exposed to the weather and having a front opening, rigid contactmembers mounted within said box, a movable cover member for the front opening hinged to the box to 25 swing vertically, a fuse tube mounted on said cover member, and multiple finger contacts mounted on said fuse tube for movement into and out of engagement with the contacts within the box upon closing and opening movements of the 0 cover member.

20. A device of the class described comprising a fuse box adapted to be exposed to the weather and having a front opening, rigid contact members mounted within said box, a movable cover 35 member for the front opening hinged to the box to swing vertically, a fuse mounted on said covermember, said fuse comprising a tubular casing of insulation having terminal ferrules thereon, and multiple finger jaw contacts mounted on said 40 terminal ferrules formovement into and out of engagement with the contacts within the box upon closing and opening movements of the cover member.

21. In a device of the class described, a fuse 45 comprising a tubular casing, a metal ferrule on said casing a fusible element within said casing, and a multiple finger jaw contact mounted in longitudinal alignment on said ferrule and projecting laterally therefrom, said contact being 50 connected to said fusible element.

22. A device of the class described comprising a tubular casing, a contact clip support mounted on the outside of said casing, a fusible element disposed within the casing and connected to said 55 clip support, and a plurality of separate spring stressed contact fingers secured to said clip support and extending laterally to present contact portions laterally of the casing.

23. In combination, a box having a back, top 0 and side walls, a cover cooperating with the top and side walls to close the front, a pair of contact blocks spaced apart vertically and mounted on the back wall, said blocks having rigid contact portions of relatively short length measured in 65 a direction normal to the back of the box, a fuse comprising a tube bearing metal ferrules, means for supporting the fuse on said cover, said ferrules having springy contact fingers anchored on that side of the axis of the tube which is nearest the 70 cover and extending beyond the side of the tube which faces the contact blocks into engagement with said contact blocks.

24. In combination, a box having a back, top and side walls, a cover cooperating with the top 75 and side walls to close the front, a pair of contact blocks spaced apart vertically and mounted on the back wall, said blocks having rigid contact portions of relatively short length measured in a direction normal to the back of the box, a fuse comprising a tube bearing metal ferrules, means for supporting the fuse on said cover, said ferrules having springy contact fingers anchored on that side of the axis of the tube which is nearest the cover and extending beyond the side of the tube which faces the contact blocks into engagement with said contact blocks, said cover being hinged at a point closely adjacent the lower end of he tube, the points of engagement of said spring contact fingers and said blocks being more remote from the pivot than the corresponding points of anchorage of said spring contact fingers.

25. In combination,.-a box, vertically aligned contacts in the box, a cover for the box, a link member comprising a fuse tube having external ferrules removabiy carried by the cover, and spring jaws carried directly on the ferrules and in longitudinal alignment and extending toward the contacts, said jaws being adapted to be moved 26 into and out of engagement with the contacts by movement of the cover to close and to open the box, respectively.

26. In combination, a box, contacts in the box a cover for the box, a connecting member having 80 ferrules thereupon, and a rigid threepoint mounting connection between said ferrules and said cover releasable only by lateral motion of the member at one of said points of mounting.

27. In combination, a. stationary rigid metal 85 contact, an arm movable toward and away from said contact, said arm bearing a cooperating contact, said latter contact comprising a rigid metallic member with a plurality of spring wires anchored upon one side of the longitudinal axis 40 of the arm and projecting beyond the other side of said longitudinal axis into gripping engagement with the first said'contact.

28. In a circuit interrupter, a pair of stationary solid metal contact blocks, means supporting said 45 blocks in insulated relation to each other, a pivoted switch element having a pair of electrically connected contact jaws held in rigid alignment to register with said contact blocks, said jaws each comprising a plurality of spring wires, each 50 wire being mounted for independent motion to adapt itself to the cooperating surface of the contact blocks.

29. In a circuit interrupter, a stationary solid metal contact block, a'movable arm, a plurality 5g of spring stressed fingers anchored for limited individual freedom upon the side of the arm remote from the contact block and extending beyond the side of thearm adjacent the contact block, said spring fingers extending into engageoo ment with the contact block.

30. In a device of the class described, a box having back, top and side walls and a cover for the front hinged to the box to swing vertically, a fuse mounted on and carried by the cover, said 05 fuse comprising a tube and ferrules, stationary live contacts mounted on the inside of the back wall of the box, and vertically aligned spring jaw means carried by the ferrules for engaging said live contacts, said live contacts lying wholly on 70 that side of the tube which faces the back wall when the cover is closed and being remote from the open front of the box when the cover is open.

31. In combination, a box, contacts in the box, a cover for the box, a connecting member having 75 ferrules thereupon adapted to make connection with said contacts, and a quick detachable threepoint mounting connection between said ferrules and said cover, said mounting being releasable by lateral movement of the connecting member in a plane substantially parallel to the cover.

32. In combination, a box, stationarycontacts in the box, a cover for the box hinged thereto to swing vertically, a link member carried by the cover, spring stressed contacts carried directly on the link and extending towards the stationary contacts, said spring stressed contacts being adapted to be moved into and out of engagement with the stationary contacts by vertical swinging movement of the cover to close and open the box respectively, and a quick detachable laterally releasable mounting connecting the link and said cover said mounting holding the link rigidly against vertical movement with respect to the cover.

33. In combination, a stationary rigid metal contact, an arm movable toward and away from said contact, said arm bearing a movable contact cooperating with said stationary contact, said movable contact comprising a rigid metallic member with a plurality 'of spring wires anchored therein, said wires projecting from said contact towards said stationary contact and into gripping engagement therewith.

34. In a device of the class described, a box having an elongated side opening, a cover for said opening, said cover being hinged to the lower end of the box, a fuse device comprising a tube having terminals, stationary line terminals in the box, said terminals of the box and of the fuse device having cooperating spring contacts, and means for carrying said fuse device on the cover of the box and into and out of conducting relation with respect to said line terminalsby opening and closing of the box, said means comprising interengaging shoulders carried by the fuse device and by the cover, respectively, said shoulders being disengageable by motion of one end of the fuse device laterally in either direction in a plane substantially parallel to the plane of the box cover, and said means holding the fuse device against motion either endwise of itself or normal to the box cover.

35. In a fuse box and fuse device, the combination of a fuse box, a cover therefor hinged to the box on a horizontal axis, a fuse device, contacts in the box cooperable with the fuse device when the cover is closed, cooperating means on the fuse device and on the cover to connect the fuse device to the cover, said means comprising a pair of spaced projections on the fuse device, and a pair of cooperating projections extending from the cover and overhanging the projections on the fuse device, said projections being disengageable only by lateral movement in either direction of at least one of the projections of the fuse device with respect to the cooperating overhanging projections on the cover.

36. The combination of claim 35 with a spring detent for yieldingly retaining the cooperating projections in holding engagement.

37. The combination of claim 23 wherein the springy contact fingers have their free ends curled toward the contact blocks which they engage.

38. The combination of claim 2'7 wherein the spring wires have their outer ends curled toward the contact blocks which they engage to provide substantially point engagement.

39. A switch comprising a substantially rigid contact block and a cooperating contact device comprising a metallic member having two rows of spring stressed fingers, the fingers of each row having the free ends thereof curled inwardly toward the other row to engage opposite sides of the block, the other ends of the spring stressed fingers of each row being rigidly held on said metallic member so that the spring fingers act as cantilevers. p

40. The combination of claim 39 wherein the 10 contact device has extending rigid arms for limiting the displacement of the spring fingers so that they will not be sprung beyond their elastic limits. I

41. The combination of claim 39-wherein the contact device has extending rigid arms at each end of each row, pins carried by the arms of each row, and the ends of the spring fingers of each row being curled about the corresponding pin whereby the pins limit the movement of the spring fingers.

42. In a fuse device, a fuse tube, and a pair of ferrules secured thereupon. each of said ferrules having a pair of spring jaws, the jaws of each pair facing each other and the pairs of jaws being endwise in alignment with the axis of the tube. 1

43. In a device of the class described, a box open at the front side, a cover therefor hinged on a horizontal axis at the bottom of the box, a

pair of block contacts in vertical alignment in the box, a fuse tube carried by the cover of the box to swing in alignment with said block confacts, and spring stressed contacts carried solely on the fuse tube and adapted to make resilient engagement with the block contacts whereby accurate longitudinal spacing of the block contacts and of the spring stressed contacts is not required.

44. The combination of claim 43, and a pair of metallic catch members on the tube and a pair 0 of cooperating catch members on the cover for releasabiy holding said tube upon said cover, said members holding the tube against endwise movement on the cover and permitting the removal of the tube by lateral movement.

45. A resilient contact member comprising a rigid metal basehaving wire receiving sockets and a plurality of contact wires having base portions inserted in and fixedly held by said sockets and having shanks extending from the rigidly held portions, said shanks terminating in contacting portions, said contacting portions comprising substantially toroidal portions for presenting substantially point contact to a cooperating contact surface.

46. The combination of claim 45 with stop means comprising a pair of pins, each pin passing through the toroidal portion of a part of said wires.

47. In combination, a pair of electrical contact members having movement relative to each other to open and close a circuit, said members comprising a jaw member and a tongue member, the jaw member having a pair of jaws facing each other and the tongue member being adapted to enter between the jaws and to be embraced thereby, said jaw member comprising a frame and a plurality of rodlike jaw contact members having curved ends adapted to engage the lateral surfaces of the tongue member, said rods having inherent resiliency tending to press against the surfaces of the tongue member, and stop means for limiting the inward motion of the rods when the tongue member is withdrawn from between them.

48. In combination, a base member having a pair of spaced bracket arms at each end thereof, spring wires disposed in rows between adjacent pairs of bracket arms, said wires having curved contact ends. the curved contact ends of each row opposing the corresponding ends of the other row, and transverse pins each held by a pair of disposed in vertical alignment within the box,

a fuse tube secured to the cover, said box having an opening at the bottom, the end of the fuse tube being disposed adjacent the hinge and adapted to be projected into said opening when the cover is closed, and spring contacts mounted on the fuse tubeand extending in a direction away from the cover to engage said blocklike contacts.

51. In combination, a box, a cover for said box, contacts in said box, an electrical connecting device carried by said cover, spring stressed contact jaws constituting the terminal members of said device mounted on and supported thereby independently of said cover, and means for mounting said cover and said connecting device for conjoint vertical rotation in such manner as to move said contact jaws into contact engagement with said contacts in said box when said, cover is closed.

52. In combination, a box having back, top and side walls, a cover cooperating with the top and side walls to close the front, a pair of contact members spaced apart vertically and mounted on the back wall, said contact members extending from said back wall a relatively short distance, a fusede'yice carried by said cover, springy contact fingers secured to said fuse device and constituting the terminal members thereof, and means for mounting said' cover and said fuse device for conjoint rotation about the lower end thereof in such manner as to move said contact fingers into contact engagement with said contact members when said cover is closed.

53. In a circuit control device, a stationary contact member, a movable arm, and a plurality of spring stressed fingers anchored for limited individual freedom upon the side of the arm remote from said stationary contact member, said spring stressed fingers extending into contact engagement with said stationary contact member.

54. In a circuit control device, a stationary contact member, a movable arm, a pair of spring stressed contact fingers disposed on opposite sides of said arm and anchored thereto along the side remote fromsaid stationary contact member, said contact fingers extending into contact engagement with said stationary contact member,

and stop means limiting the movement of said contact fingers to positions slightly within the path of relative movement thereof with said stationary contact member.

55. A fuse device of the class described comprising, a tubular casing of insulation for housing a fusible element, said casing being closed at one end and open at the other, a plurality of spring stressed contact fingers mounted upon the outside of said tubular casing and extending laterally with respect thereto, said contact fingers being supported by said casing for connection with said fusible element, and means for holding said tubular casing against endwise movement independently of said contact fingers.

56. A device of the class described comprising, a

tubular casing for housing a fusible element, a

contact clip support mounted on the outside of said casing for connection to said fusible element, and a pair of spring stressed contact fingers secured to said clip support on opposite sides of said casing and extending laterally to present contact engaging portions laterally of said casing.

57. In a fuse device, a fuse tube disposed to be mounted adjacent a contact member, and spring stressed contact fingers secured to said fuse .tube only along the side thereof remote from said contact member and otherwise spaced therefrom and extending in the direction of the opposite side of said fuse tube for contact engagement with said contact member.

58. In a fuse device, a fuse tube for housing a fusible element and disposed to be mounted adjacent a contact member, and prestressed contact fingers carried by said fuse tube for connection to said fusible element and contact engagement with said contact member.

59. In a fuse device, a fuse tube for housing a fusible element anddisposed to be mounted adjacent a contact member, flexible spring stressed contact fingers carried by said fuse tube for connection to said fusible element and contact engagement with said contact member, and means for limiting the movement of said spring stressed contact fingers to prevent distortion beyond a predetermined amount when said contact engagement takes place.

60. In combination, a stationary contact memher having a pair of spaced contact surfaces supported in fixed position relative to each other, a

relatively movable contact member comprising a rigid support and a pair of spring stressed contact fingers, said fingers being fixed at one end to said rigid support and extending in the same direction and having contact surfaces ad- J'acent their outer ends coacting with the contact surfaces on said stationary contact member, the contact surfaces of one of said contact members being convex with respect to the other to reduce the area of actual contact engagement, the contact surfaces of one of said contact members facing away from each other and the contact surfaces of the other contact member facing toward each other, lost motion means limiting the traverse of said contact fingers under the spring stress, and means arranged and adapted to move said movable contact member into and out of engagement with said stationary contact member substantially longitudinally of said contact fingers.

61. In combination, a stationary contact member having spaced contact surfaces, a relatively movable contact member comprising a rigid supporting element and a pair of spring stressed contact fingers extending therefrom,

said fingers being secured at one end and having high pressure contact surfaces of small area at their other ends, the contact surfaces of one of said contact members facing toward each other and the contact surfaces of the other contact member facing away from each other, lost motion means limiting the movement of said contact fingers relative to said contact surfaces of said stationary contact member, and means ar- 75 ranged and adapted to effect relative movement of said contact members substantially longitudinally of said contact fingers.

62. In combination, a stationary contact member having a pair of spaced contact surfaces in fixed position relative to each other, and a cooperating movable contact member comprising a rigid metallic supporting element having a plurality of contact fingers rigidly anchored to said supporting element at one end and having their other ends extending substantially parallel to' each other for engaging said contact surfaces substantially along lines in a plane perpendicular to said spaced contact surfaces and perpendicular to the direction of relative movement of said contact members, and lost motion means at the outer ends of said fingers for limiting the movement of said fingers with respect to said contact surfaces of said stationary contact member, said fingers being urged resiliently against said lost motion means when the contact members are separated and being urged resiliently against said contact surfaces when said contact members are in engaging relation.

63. A movable contact member for engaging a stationary contact member having a pair of spaced apart contact surfaces comprising, a rigid metallic supporting element, and a plurality of pairs of individually flexible and individually spring stressed contact fingers each fixed at one end on said supporting element and extending substantially in the direction of relative movement of said contact members and having a small area contact surface adjacent the other end for engaging said contact surfaces of said stationary contact member.

64. A movable contact member for engaging a stationary contact member having a pair of spaced apart contact surfaces comprising, a rigid metallic supporting element, a plurality of pairs of individually flexible and individually spring stressed contact fingers each fixed at one end on said supporting element and extending substantially in the direction of relative movement of said contact members and having a small area contact surface adjacent the other end for engaging said contact surfaces of said stationary contact member, means limiting the movement of said contact fingers to positions slightly within the path of relative movement with said stationary contact member, and means preventing distortion of said contact fingers in a direction opposite to said movement.

65. In combination a relatively rigid stationary contact member, and a relatively yielding multiple contact member mounted for movement with respect to said stationary contact member, said movable contact member comprising a rigid metal base, a plurality .of flexible wires having mounting ends rigidly fastened into said base for mechanical anchorage and for conduction of current thereto, said multiple contact member being movable substantially endwise along'the length of the Wires to slidably engage a lateral surface of said stationary contact member, said wires having portions adjacent their outer ends bent to provide limited engagement of each wire with the cooperating surface of said stationary contact member, said wires providing multiple limited area high pressure contact engagement with said stationary contact member, said wires adjacent their points of engagement with said stationary contact member being provided with 'means for limiting the deflection of said wires in the direction of said engagement whereby said wires are held in prestressed condition before said engagement takes place 66. In combination, a stationary contact member having a contact surface facing outwardly, 5 a relatively movable contact member comprisinga rigid supporting element and a plurality of prestressed contact fingers extending therefrom, said fingers being'securedat one end and having highpressure contact surfaces of small 10 area at their other ends, said high pressure contact surfaces facing inwardly for engagement with said outwardly facing contact surface of said stationary contact member, and means for effecting relative movement between said conl5 tact members substantially longitudinally of said contact fingers.

67. A movable contact member for engaging a stationary contact member having a contact surface comprising, a rigid metallic supporting ele- 20 ment and a plurality of prestressed contact fingers arranged in a line, said fingers being secured at one end to said supporting element and extending in the same direction substantially along the line of relative movement of said contact 25 members and having contact surfaces of limited area at their outer ends for contact engagement with said contact surface along a line in a plane substantially normal thereto.

68. In combination, a stationary, contact member having a pair of spaced apart contact surfaces, a relatively movable support member, a pair of spring stressed contact fingers fixed at one end on said support member. and extending in the same direction and having contact surfaces -3 adjacent the other ends for engaging the contact surfaces of said stationary contact member, stop means limiting the movement of said contact fingers to positions slightly within the path of relative movement with said stationary con- 40 tact member, the portions of said contact surfaces first engaged by said contact fingers being curved in such manner as to lift them off of said stop means and move them out of said path on further movement thereof toward said station- 45 ary contact member, and means arranged and adapted to move said support member substantially longitudinally of said contact fingers.

69. In combination, a stationary contact member having a pair of spaced apart contact sur- 50 faces, a relatively movable support member, a

plurality of pairs of individually flexible and individually spring stressed contact fingers each fixed at one end on said support member and having a small area contact surface adjacent the 55 other. end for engaging said contact surfaces of said stationary contact member along lines in a plane substantially normal thereto and to the path of relative movement of said contact members, and stop means limiting the movement of 0 said contact fingers to position the small area contact surfaces thereof slightly within the path ofrelative movement with said stationary contact member, the portions of said spaced apart contact surfaces first engaged by said small 65 area contact surfaces of said contact fingers being curved in such manner as to lift said contact fingers oii" of said stop means and move them out of said path on further movement thereof towardsaid stationary contact member.

7 70. In combination, a stationary contact member, a relatively movable support member, a pluaoaiasa rality of; individually flexible and individually spring stressed contact fingers each fixed at one end on said support member and having a small area convex contact surface adjacent the other end for engaging said stationary contact member, stop means limiting the movement of said contact fingers to position the small area contact surfaces thereof slightly within the path of relative movement with said stationary contact member, whereby slight misalignment between said stationary contact member and said support member does not cause change in the contact engagement between said stationary contact member and said contact fingers, and means arranged and adapted to move said support member substantially longitudinally of said contact fingers.

71. In a circuit control device, in combination, a stationary contact member, an arm pivoted at one end for swinging in a plane, a plurality of individually flexible and individually spring stressed contact fingers each fixed at one end on said arm and extending transversely thereto and having a small area convex contact surface adjacent the other end for engaging said stationary contact member, and stop means limiting the movement of said contact fingers to position the small area contact surfaces thereof slightly within the path of relative movement with said stationary contact member, whereby slight misalignment between said stationary contact member and said pivoted arm does not cause change in contact engagement between said stationary contact member and said contact fingers.

72. In combination, a box, a pair of contact members in vertical alignment in said box, a fuse tube, means hinged to said box and supporting said fuse tube to swing the same substantially in alignment with said contact members, terminals carried by said fuse tube, a plurality of individually flexible and individually spring stressed'contact fingers carried by each of said terminals, each contact finger being fixed at one end on its terminal and having a small area convex contact surface adjacent the other end for engaging said contact members, and stop means limiting the movement of said contact fingers to position the small area contact surfaces thereof slightly within the path of relative movement with said stationary contact members, whereby slight misalignment between said stationary contact members and said fuse tube does not cause change in contact engagement between said stationary contact members and said contact fingers.

73. In a fuse device, in combination, a pair of terminals each having a wedge shaped conductor receiving portion, a fuse link, conductors extending from each end of said fuse link and arranged and adapted to interfit with. said terminals in the wedge shaped conductor receiving portions thereof, and a spring t'ensioning said fuse link.

74. In a fuse device, in combination, a pair of terminals each having a wedge shaped conductor receiving portion, a fuse link, conductors extending from each end of said fuse link and arranged and adapted to interfit with said terminals in the wedge shaped conductor receiving portions thereof, and a spring operatively connected to one of said terminals and acting to tension said fuse link.

ALLAN RAMSEY. 

